PET film is widely used in beverage and beer fields in developed countries as an environmentally friendly packaging material with low cost, high productivity, excellent appearance and efficient logistics. The use of beverage and beer work in China is also increasingly widespread.

The annual consumption of PET film in Europe is more than 400,000 tons. The author has visited PLASTO, the third largest shortening film supplier in Europe. Its annual output in 2003 was 55,000 tons, and the printed PE colorful shortening film was 28,000 tons. tons, exceeding the output of 27,000 tons of unprinted PE shortening film (commonly known as white film or plain film in the industry). Its detailed composition is 28,000 tons of printed color film, accounting for 51%; other: 6,100 tons for glass bottle packaging, accounting for 11%; 8,600 tons for packaging paper packaging, accounting for 15%; 8,600 tons for milk packaging, accounting for 15% %; 3,700 tons are used for packaging of building materials such as bricks and tiles, accounting for 6%.

Since the domestic beer industry has prevented the use of bundled beer, PE shortened film packaging has appeared in the market at a low cost, and its use has increased year by year; then with Coca-Cola's implementation of PE shortened film in China to replace carton packaging, it has expanded from beer work to beverage work. . With the increasingly fierce competition in the terminal market, the low-cost advantage of PE shortened film packaging is increasingly favored by manufacturers. At first, the PE shortening film appeared in the market in the form of transportation packaging. After being transported to the sales terminal, it needs to be sold as a single piece after breaking the package. However, with the change of purchasing methods in recent years, the direct sales trend of assembled packaging has become more and more obvious. The shelf display effect of the shortened film before printing provides packaging manufacturers with an excellent opportunity to increase the added value of the PE shortened film.

At that time, the annual use of PE shortening film in China's beverage and beer industry was about 100,000 to 150,000 tons, accounting for about 50% of carbonated beverages, 20% of hot canned beverages, 15% of bottled water and 5% to 8% of beer. shopping mall ratio. With the rapid development of beverage and beer industry and the growth of PE shrink film market proportion, it is estimated that in 2010 China's PE shrink film annual usage will exceed 600,000 tons, becoming the world's largest PE thermal shrink film market. The annual usage of printed PE shortening film is about 2000-2500 tons, which only accounts for about 2% of the market share of PE shortening film.

The PE shortening film is mainly produced by using LDPE with a melt index lower than 1 and using the single-bubble blown film technology to control the vertical and horizontal shortening rate of the PET film through formulation, blow-up ratio, die head space and cooling. The primary technical parameters of PET film are shortening rate, physical and mechanical properties, coefficient of friction and suitability for packaging machines. There are national standards for physical and mechanical properties such as shrinkage rate and tensile strength. The coefficient of friction primarily affects the stacking stability of packaged goods. The suitability of packaging machines is the most important policy for PE shortening films. Whether the packaging machine can be used and the power used is mainly affected by the formulation of the PET film, but to a greater extent by the description level of the packaging machine.

At that time, the manufacturing level of China's single-bubble PE film blowing machine has reached or approached the international first-class level. The author used the domestic three-layer co-extrusion film blowing machine equipped with film bubble inner cooling to produce a thickness error of ±5%, and a shortening rate error of ± 3% high-transparency PET film, of course, for ordinary PE thermal shortening film that does not need to be printed, a single-layer film blowing machine can fully meet the needs of the product. Judging from the experience in Europe and the production experience of printing shortening films in China at that time, due to the thermal shrinkage characteristics and easy extension characteristics of PET films, the printing requirements of PE thermally shortened PET films need to be printed by satellite flexo printing machines. However, the equipment of satellite flexo printing machines in China was very lacking at that time, which would be the primary factor restricting the development of printing PE thermal PET film.

The LDPE used as the main material was only produced by a few manufacturers such as Yanshan Petrochemical in China at that time, and most of them relied on imports, and the quotation was very unstable. In the long run, the demand for LDPE in China is increasing day by day. However, both China and the whole world, the newly opened polyethylene factories in 2008 are LLDPE and HDPE factories, and no new LDPE factories have been opened, which is expanding virtually. The most worrying point is the supply gap of LDPE.

At that time, under the premise that China had equipment and other hardware, and the market demand was growing, the development of PET film would be subject to the supply of LDPE.